The present invention relates to a defect inspection method and a defect inspection device where an infinitesimal defect that exists on a surface of a sample is inspected, a position, a type and dimensions of the defect are determined, and a result of the determination is output.
To maintain and enhance the yield of a product in a manufacturing line for a semiconductor substrate, a thin film substrate and others, the inspection of a defect that exists on a surface of the semiconductor substrate, the thin film substrate and others is performed. For prior art for the defect inspection, technique disclosed in Japanese Unexamined Patent Application Publication No. Hei 8-304050 (Patent Literature 1), Japanese Unexamined Patent Application Publication No. 2008-268140 (Patent Literature 2) and others is known.
In Patent Literature 1, it is described that detection sensitivity is enhanced by illuminating the same defect plural times in one inspection by an illumination optical system that linearly illuminates and a detection optical system that divides and detects an illuminated region on a line sensor and adding their scattered light.
In Patent Literature 2, it is described that 2n pieces of APDs corresponding to a laser beam band are linearly arrayed, appropriate two of 2n pieces are combined, the difference between output signals of the two APDs in each combination is calculated, noise by reflected light is eliminated, and a defective pulse for scattered light is output.